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Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
Paramagnetic rims are a promising diagnostic imaging biomarker in multiple sclerosis
Isobel Meaton1, Amjad Altokhis1, Christopher Martin Allen1
1Mental Health and Clinical Neurosciences Academic Unit, School of Medicine, University of Nottingham, Nottingham, UK.
Background:
White matter lesions (WMLs) on brain magnetic resonance imaging (MRI) in multiple sclerosis (MS) may contribute to misdiagnosis. In chronic active lesions, peripheral iron-laden macrophages appear as paramagnetic rim lesions (PRLs).
Objective:
To evaluate the sensitivity and specificity of PRLs in differentiating MS from mimics using clinical 3T MRI scanners.
Method:
This retrospective international study reviewed MRI scans of patients with MS (n = 254), MS mimics (n = 91) and older healthy controls (n = 217). WMLs, detected using fluid-attenuated inversion recovery MRI, were analysed with phase-sensitive imaging. Sensitivity and specificity were assessed for PRLs.
Results:
At least one PRL was found in 22.9% of MS and 26.1% of clinically isolated syndrome (CIS) patients. Only one PRL was found elsewhere. The identification of ⩾1 PRL was the optimal cut-off and had high specificity (99.7%, confidence interval (CI) = 98.20%-99.99%) when distinguishing MS and CIS from mimics and healthy controls, but lower sensitivity (24.0%, CI = 18.9%-36.6%). All patients with a PRL showing a central vein sign (CVS) in the same lesion (n = 54) had MS or CIS, giving a specificity of 100% (CI = 98.8%-100.0%) but equally low sensitivity (21.3%, CI = 16.4%-26.81%).
Conclusion:
PRLs may reduce diagnostic uncertainty in MS by being a highly specific imaging diagnostic biomarker, especially when used in conjunction with the CVS.
Insights
Paramagnetic rim lesions (PRLs) show high specificity in diagnosing multiple sclerosis (MS) and clinically isolated syndrome (CIS). Combining PRLs with the central vein sign (CVS) further enhances diagnostic accuracy for MS.
Area of Science:
- Neurology
- Radiology
- Medical Imaging
Background:
- White matter lesions (WMLs) in multiple sclerosis (MS) brain MRI can lead to misdiagnosis.
- Peripheral iron-laden macrophages in chronic active MS lesions manifest as paramagnetic rim lesions (PRLs).
Purpose of the Study:
- To assess the sensitivity and specificity of PRLs in distinguishing MS from mimic conditions.
- To evaluate PRLs using standard clinical 3T MRI scanners.
Main Methods:
- Retrospective analysis of MRI scans from patients with MS (n=254), MS mimics (n=91), and healthy controls (n=217).
- WMLs detected via fluid-attenuated inversion recovery MRI were analyzed using phase-sensitive imaging.
- Sensitivity and specificity of PRLs were calculated.
Main Results:
- PRLs were present in 22.9% of MS and 26.1% of CIS patients; only one PRL was found in other groups.
- Identifying ≥1 PRL demonstrated high specificity (99.7%) for differentiating MS/CIS from mimics/controls, but low sensitivity (24.0%).
- PRLs with a central vein sign (CVS) were exclusively found in MS/CIS patients, yielding 100% specificity but 21.3% sensitivity.
Conclusions:
- Paramagnetic rim lesions (PRLs) serve as a highly specific imaging biomarker for reducing diagnostic uncertainty in MS.
- The combination of PRLs and the central vein sign (CVS) further improves diagnostic specificity in MS.
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